Tony Abbott's comments on same-sex marriage laws mostly true

Some state governments have raised the prospect of bringing in their own same-sex marriage laws.

On July 28, 2013, Opposition Leader Tony Abbott was asked by a reporter:

"A state parliamentary committee has found that states could pass same-sex marriage laws. Do you think it is appropriate for the state to do that rather than it happen at a federal level?"

Mr Abbott responded:

The claim: Tony Abbott says marriage is a responsibility of the Commonwealth parliament.

The verdict: The states can make laws allowing same-sex marriage, but it's unclear whether those laws would stand if challenged in the High Court.

"What the states do is a matter for the states. The constitution provides that marriage is a responsibility of the Commonwealth parliament. And as you know the Commonwealth parliament recently voted on this subject and by a fairly decisive margin decided to stick with the existing Marriage Act."

ABC Fact Check investigated whether Mr Abbott was right to focus on marriage being a Commonwealth responsibility.

Submissions to the inquiry from legal experts did not agree on whether a state same-sex marriage law would be inconsistent with the existing Commonwealth law.

Some argued there would be no inconsistency because Canberra's power is confined to opposite-sex marriage.

Others argued that the definition of marriage in the constitution evolves over time and therefore the Commonwealth is able to legislate on all types of marriage, and a state law seeking to cover the same ground as the Commonwealth law would be invalid.

In any case, any law introduced by a state could be challenged in the High Court as unconstitutional.

The NSW committee's report said it was uncertain what the outcome of such a challenge would be "and therefore equal marriage rights for all Australians may best be achieved under Commonwealth legislation".

The verdict

The constitution does provide that marriage is a responsibility of the Commonwealth, but the power is not exclusive and the law surrounding the issue is not straightforward.

It is unclear if a state-made law on same-sex marriage would stand if challenged in the High Court.

Fast facts

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